Baculovirus production

Profilin (PROF) is a small actin-binding protein presented in apicomplexan protozoa. It was previously reported that Neospora caninum profilin (NcPROF) is secreted into the hemolymph of silkworm larvae regardless of the lack of an identified regular secretion signal peptide. To date, which domain is required for its secretion still remains unknown. To this end, we express a fluorescent protein (mCherry) fused with NcPROF at its N-terminus or C-terminus. Both fusion proteins were expressed and secreted into the culture supernatant from Bm5 cells or hemolymph from silkworm larvae, respectively. To further narrow down the C-terminal minimal domain required for its secretion, we constructed three truncated C-terminal domain constructions,